One form of the present invention relates to a data storage device capable of inputting or outputting processing data even when a plurality of storage media are faulty simultaneously.
Another form of the present invention relates to a reconstruction controlling device that controls an operation of reconstructing stored data in the above-described data storage device.
Another form of the present invention relates to a reconstruction controlling method that controls an operation of reconstructing stored data in the above-described data storage device.
Another form of the present invention relates to a storage medium for storing a program that implements an operation of reconstructing stored data in the above-described data storage device.
A data storage device handing a large amount of digital data on a daily basis uses a processing technique that can read and write processing data at high speed and a processing technique that enhances availability.
For example, the processing technique that can read and write processing data at high speed uses a striping system. The striping system refers to a technical method that divides one piece of processing data into a plurality of processing units and simultaneously reads or writes these processing units on a plurality of storage media arranged in parallel with each other.
For example, the processing technique that enhances availability uses a redundant data storing system. One example of the redundant data storing system is a method of storing error correcting code (parity code) used for error correction or restoration of processing data. Another example is a method referred to as mirroring.
Currently mainstream storage media of high-capacity storage devices are magnetic storage media (hard disks). The above-described data storage device is therefore referred to also as a disk array device. Incidentally, a technology that enhances the availability of a disk array technology is referred to as RAID (Redundant Arrays of Inexpensive Disks). Examples of applications for disk array devices by the applicant are shown in Patent Document 1 and 2 (See Japanese Patent Laid-open No. 2000-66845 as Patent Document 1 and Japanese Patent Laid-open No. Hei 11-45158 as Patent Document 2).